[Near infrared distance sensing method for Chang'e-3 alpha particle X-ray spectrometer].

Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover, the scientific objective of which is in-situ observation and off-line analysis of lunar regolith and rock. Distance measurement is one of the important functions for APXS to perform effective detection on the moon. The present paper will first give a brief introduction to APXS, and then analyze the specific requirements and constraints to realize distance measurement, at last present a new near infrared distance sensing algorithm by using the inflection point of response curve.

[Temperature effect correction for Chang'E-3 alpha particle X-ray spectrometer].

Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover of China's Lunar Exploration Project. The present paper introduces briefly the components of APXS, how it works and its working environment on the lunar surface. The environmental temperature effect has been studied with simulations and experiments, and the results show that the temperature of the APXS sensor will be varying during the measuring on the lunar surface.

[Application of direct demodulation technique in analysis of ground verification test of x-ray spectrometer for Chang'e mission].

An X-ray fluorescence imaging spectrometer based on silicon PIN photodiodes was designed and constructed for the Chang'E mission, the first lunar spacecraft, and will be in operation at a 200 km circular lunar orbit with one year lifetime. The X-ray fluorescence spectrometer consists of two silicon PIN photodiodes modules, each holds two low energy detector units to analyze the distribution of useful elements and to estimate the abundance on the moon, which is one of the objectives of the X-ray fluorescence spectrometer experiment. The low energy detector unit is 25 mm2, 500 microm thick, with the energy band of 1-10 keV, and energy resolution of: approximately 5% at 5.